Spatial average of a variable at selected grids-Regd.
Added by Naveen Pothula over 4 years ago
Dear all,
I have a .nc file spread over a large area at 0.5 x 0.5 resolution on regular lonlat grids. I want to take the average of the variable for selected grids. The grids are continuous but when put together they don't form a perfect rectangle. Is this possible to do in cdo. kindly give a solution, other wise I have to extract the data for the grids individually and then do the average.
Kindly help,
naveen.
Replies (3)
RE: Spatial average of a variable at selected grids-Regd. - Added by Karin Meier-Fleischer over 4 years ago
Hi Naveen,
you can use collgrid to reunion the region files.
Example:
Create an example data file topo_area.nc:
cdo -f nc -sellonlatbox,0,60,30,80 -topo topo_area.nc
Split data file into regions (-distgrid,nx,ny)
cdo -distgrid,3,2 topo_area.nc topo_parts
Loop: compute the timmean of each file
for f in $(ls topo_parts*.nc); do; cdo -timmean ${f} avg_${f}; done
Collect the regions (-collgrid,nx)
cdo -O -collgrid,3 avg_*.nc outfile.nc
-Karin
RE: Spatial average of a variable at selected grids-Regd. - Added by Naveen Pothula over 4 years ago
Dear Karin,
My intention is to get the spatial average of a variable at selected grids at different time steps. I don't intend to take the time mean.
I want to select a group of grid cell and take the spatial average at different time steps (same timesteps as individual grid).
Kindly suggest a solution.
best wishes,
naveen
RE: Spatial average of a variable at selected grids-Regd. - Added by Karin Meier-Fleischer over 4 years ago
Sorry, for this case you have to do it step by step.